CHANGES IN SNORING CHARACTERISTICS AFTER 30 DAYS OF NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE IN PATIENTS WITH NON-APNEIC SNORING - A CONTROLLED TRIAL

Background - A study was performed to evaluate the effect of discontin uation of nasal continuous positive airway pressure (NCPAP) treatment on snoring characteristics. Methods - Eighteen non-apnoeic snoring sub jects were randomly allocated to either a no treatment control group o r an NCPAP treatment group. The control group was studied twice (basel ine and day 30 of follow up). In the NCPAP group the level of NCPAP th at abolished snoring was determined and patients were placed on NCPAP every night for one month. A sleep study was performed on the first ni ght without NCPAP after completing 30 days of treatment (follow up 1). A fourth polysomnographic study was performed 8-10 days after NCPAP w as stopped (follow up 2) in six subjects. Results - In both groups tot al sleep time (TST) and sleep architecture remained unchanged at the d ifferent visits. Baseline snoring characteristics in the two groups we re similar. In the control group the mean (SE) number of snoring episo des/hour of sleep (snoring index) and the percentage of TST > 60 decib els (dB) were 380 (36)/h and 11.1 (2.0)% TST respectively at baseline, and was unchanged at follow up. In the NCPAP group the snoring index decreased from 387 (50)/h to 320 (57)/h after NCPAP therapy, but the % TST > 60 dB decreased from 10.3 (1.8)% to 7.4 (1.5)%. The snoring ind ex and intensity returned to baseline values at follow up 2 (374 (74)/ h, 9.8 (2.1)% TST). Changes in snoring characteristics could not be ex plained by changes in body position between the different sleep studie s. Conclusions - NCPAP improves snoring but this effect is lost soon a fter stopping treatment.